Consumer perceptions of egg quality
The European Consumer Association (BEUC) has indicated some of the attributes (food quality factors) that are valued by consumers but, until recently, there had been little detailed information published specifically regarding consumer perception of egg quality. However, data from consumer surveys performed over recent years has added greatly to our knowledge in this area.
In 2001, a study involving 3085 people was performed in Spain with the specific objective of validating and ranking in eggs those attributes proposed by the BEUC. Not surprisingly, the survey showed that for consumers, ‘safety’ and ‘freshness’ were the most important quality factors, with ‘nutritional value’ and ‘sensory characteristics’ also being key parameters. With regards to ‘sensory characteristics’, the results of surveys performed over the last 10 years in a number of European countries (France, Germany, Italy, UK, Spain, Poland and Greece) indicate that consumers value a number of tangible characteristics of the egg, most especially shell strength, albumen consistency and yolk colour.
Yolk colour, both in terms of the colour per se and the variability in colour among eggs, is a very important parameter by which consumers judge the quality of eggs.
In the surveys, when offered samples of eggs with different yolk colours (measuring 8, 10, 12 and 14 on the DSM Yolk Colour Fan (YCF), the majority of the people questioned in all countries expressed a preference for the egg yolks with the darkest colour hue (colour score 14). Yolk colour in laying hens is primarily determined by the content and profile of pigmenting carotenoids present in their feed and can easily be adapted via feed ingredients to match consumer preferences.
In this regard, it is surprising to note that in data published in 2004 by an independent quality control laboratory auditing eggs for supermarkets in Spain (analysis of 12 000 eggs during 2002/3), yolk colour showed the highest non-compliance to egg quality specifications (8.8% eggs below specification). There are several explanations as well as some potential solutions which may help minimize this effect. In many cases, egg producers understand the target yolk colour as the average yolk colour they need to obtain.
Taking the example of an egg producer with a target DSM-YCF score of 12 (tolerance -1) in their retail specification, by producing eggs to the target (DSMYCF score 12), a percentage of the eggs produced will fail against the retail specification due to normal biological variation.
The most straightforward way to counteract this and avoid such a high level of non-compliances is to increase the average yolk colour of the total egg production. In addition to inherent biological variation, it is also important to minimise the effect of other factors which can also reduce the consistency of the yolk colour produced — the wider the distribution of yolk colours about the mean value, the higher will be the potential for non-compliance with the retailer specification.
For example, in order to achieve both the target level and homogenous distribution of the carotenoids in the feed, it is important to use reliable, uniform products which have both good stability (commercial product forms/premix/feed) and mixability characteristics.
Likewise, it is also important to provide an adequate level of yellow carotenoids in the feed to provide a good yellow base for the development of the required golden yellow colour in the egg yolk. By achieving the correct levels of the most appropriate carotenoids in the feed, it is possible to routinely achieve the yolk colour expected by consumers while at the same time minimizing the degree of variability and thereby reducing the potential for noncompliance.
How can you tell if an egg is fresh? What does the stamp on the egg mean? Do brown eggs taste better? What does the colour of the egg yolk say about the hen? What tasty dishes can I cook up using eggs? Are you able to explain to your kids how a hen makes an egg?
Now there is a website, www.yellow-egg.com, accessible to everyone in the food chain to try to help you find most answers. The yellow-egg web site is currently available in English, Spanish, Italian, German, French and soon in Russian, Portugese, Polish and Japanese.
Why are egg yolks yellow?
Food doesn’t just have to taste good, it has to look good too: blue milk, green meat, and violet butter don’t stand a chance under our critical gaze. Everything that we eat has to look good, smell good, taste good, and have the right consistency. Especially when it comes to egg yolks, we love a golden yellow. But where does this golden yellow come from? What are carotenoids, and what role do they play in nature?
What are carotenoids?
In 1931, the chemist Heinrich Wackenroder was the first to discover a carbon compound in carrots, naming it “carotene”. We now know of some 650 carotenoids, without which natural life would be impossible. These substances are responsible, for example, for the yellow to reddish-orange colours of fruit and vegetables, for the vibrant hues of fl owers and for many a colourful coat in the animal kingdom. Plants, fungi and bacteria around the world produce some three tons of carotenoids every single second.
In nature, carotenoids are much more than just colourants. They also perform vital protective and regulatory functions. Neither humans nor animals are capable of producing carotenoids themselves; we need to take them in with our food. Around fifty of these valuable colorants are important for humans as pro-vitamin A, meaning that they can be converted into vitamin A. Some of carotenoid’s biological functions are:
The SQTS Concept
SQTS means the way chosen by leading companies to manufacture their feed ingredient portfolio, carotenoids being a good example of it: the best way to guarantee safety, quality, traceability and sustainability to the Food Chain.
“S” for Safety
Hen feed ingredients are manufactured according to the highest possible standards and production is subject to strict monitoring. Of course, this also applies to carotenoids. It sees to the hen’s health and gives the egg its “heart of gold” — a golden yellow yolk.
“Q” for Quality
Globally, around one thousand billion eggs are consumed every year. Numerous consumer surveys show that the colour of the yolk is a distinct sign of quality. Consumers want eggs with consistently coloured egg yolks. We first notice yolk quality at the breakfast table, but it is around long before that: through hen feed enriched with carotenoids the farmer is able to influence the homogeneity and intensity of the yolk colour.
“T” for Traceability
In the EU every egg is individually stamped. The codes are standardized throughout the EU and allow the egg to be traced through an unbroken chain back to the farm where it was laid. This protects consumers and egg farmers in equal measure. Transparency in the entire food chain guarantees optimum safety for egg consumers. This high standard of safety also applies to responsible companies producing feed ingredients for the egg chain. Every product and feed ingredient must be traced back to its origin.
“S” for Sustainability
Just as an example, did you know that in order to ensure the global need for vitamin C, 30% of the earth would have to be covered by orange groves? Sustainable agriculture secures our standard of living – without devastating our natural reserves. The same would happen with any other feed or food ingredient identical to those found in nature and manufactured using the most modern production methods. This conserves the environment and ensures us a comfortable and healthy life. Sustainable agriculture, for the environment’s sake.
© The State of Queensland, Australia (through its Department of Primary Industries and Fisheries) and DSM Nutritional Products Ltd., 2007. No part of this publication may be reproduced, copied or transmitted save with prior written permission of Director, Intellectual Property Commercialisation Unit, Department of Primary Industries and Fisheries, GPO Box 46 Brisbane, Queensland, Australia 4001, and DSM Nutritional Products Ltd.